Steam-generator and water-heater.



No. 575,719. Patented lune 4, |90I. C. E. DAWSON.

STEAM GENERATOR AND WATER HEATER.

(Application led Dec. 8, 19Go.)

(No Model.)

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CHARLES ERNEST DAIVSON, OF CIIISIVICK, ENGLAND.

S'l'hAlW-GENERATOR AND VVATERWEIATER.

EEGIFICATION forming part of Letters Patent No. 675,719, dated June 4, 1901.

Application filed December 8, 1900. Seria-l Nrn-39,173. (Ilo model.)

To (all wtmn t Nen/,7,1 concern:

Beit known that l, CHARLES ERNns'r DAW- soN, engineer, a subject of the Queen of Great Britain and Ireland, residing at Hogarth lVorks, Chiswick,i1itlie county of Middlesex, England, have invented certain new and useful Improvements in Steam-Generators and Tater-Heaters, (for which Ihave made application for patent in Great Britain, No. 8,507, dated May 8, 1000,) of which the following` is a specification.

My invention relates to the type of boilers known as tubulous or water-tube boilers, and has for its object to provide a light and simple boiler in which a high rate of evaporation may be attained and to enable the boiler and furnace or source of heat to be placed exceedingly close together, while securing a nearly complete absorption of the heat generated from the fuel.

My invention consists in making the spaces between the tubes or coils exceedingly small and supporting the coils in such a way that the only exit from the furnace or fire-box is through these very narrow spaces. Provided the width of these spaces be sufficiently small, the furnace gases when forced or drawn through them completely or almost completely give up their heat to the water being circulated in the coils and practically no flame can pass through them. This screen of coils forming the boiler I place quite close against the top of the lire, and I use either forced or induced draft to insure satisfactory combustion. The circulation in the boiler is produced by the expansion of the water into steam in the case of steam-boilers and by the forced circulation of the water in the case of water-heaters, water being supplied, preferably, by a force-pump of any suitable construction. Forced circulation may, however, be used for the steam-generator.

In carrying my invention into eifect according to one modification, as represented in central vertical section in the accompanying drawing, I form a boiler of one continuous coil of pipe a, preferably flattened in section in the direction of the axis of the coil. This coil may be either flat or, as shown in the drawing, of volute or slightly-conical form, with the apeX or smaller end at the top. I support this coil c on lfire-clay supports or on an almost complete circularl wall Z), of fireclay, and I close the space c within the center or innermost coil with a fire-clay block d, which may be supported in position in any convenient manner. If desired, suitable stays or frames may be provided to prevent the coil from sagging or becoming distorted.

I place the fire-bars c within a very small distance of the coil a to allow just sufficient room for the fuel, which almost entirely fills the furnace -space The whole boiler and furnace is included in a light steel or wrought iron casing f, provided with a fire-door g and a chimney or outlet-tlue h. The ash-pit 'L' beneath the lire-bars e is provided with a doorj, which may be closed when forced draft is desired and opened when induced draft is employed. The wall b closes the space be tween the outermost coil of the pipe c and the casingf, excepting above the fire-door g, where it is closed by means of other fire-clay blocks or in any other convenient manner.

If desired, instead of the fuel being sup plied to the furnace at the side, as shown in the drawing, it may be supplied Afrom the top, for which purpose the block CZ would be movable, so that it could be lowered to allow fuel to be fed through the central space o and raised to close the space after charging.

7s is the feed-water inlet, and Z the steam or hot-water outlet, of the boiler.

The inlet or pipe 7o may be connected to a suitable water-heater,in which all lime and other deposit may take place, so as to insure the inside of the coil a being kept free from deposit. Such water-heater may take the form of a coil or series of coils arranged above the coil a. In connection with the outlet or pipe Z I provide a separator or steam-trap to separate suspended water from the dry steam and to collect any mineral deposit and other matter which by reason of the rapid circulation are carried through the coil d.

I find that with such a boiler as that just described if the spaces between the coils a be small enough a condition may be arrived at in which the gases passing through these spaces are deprived almost entirely of their heat, which passes into the water, provided sufficient Water circulation is kept up to Inaintain the coils at a comparatively low temper# ature and the forced or induced draft is kept IOO up. The spaces between the coils must be of such dimensions that no iiame can pass through them, and in practice I find that the temperature above the coil is very low and that almost complete absorption of the heat by the coil or' the coil and water takes place.

Having now described my invention, what Iclaim as new, and desire to secure by Letters Patent, is-

l. The combination of a tubulous waterheater or boiler having spaces between the tubes sufficiently restricted to prevent flame passing through them, a casin g for the heater, having an outlet for the products of combustion, and a combustion-chamber in the cas ing located wholly below the said tubes and communicating with the outlet only through the restricted spaces.

2. In a water-heater the combination with a coiled tube having spaces between adjacent coils suiiiciently restricted to prevent Hanne passing through them, of a casing for the coiled tube having an outlet for the products of combustion, and a combustion-chamber located wholly below the said tubes and communicating with the outlet only through the restricted spaces.

3. In a water-heater the combination with a tube of flattened section coiled in volute or conical form about an axis parallel with the iat surfaces of the tube and having spaces between adjacent coils suiiiciently restricted to prevent iiame passing through them, of a casing for the coiled tube having an outlet for the products of combustion, and a combustion-chamber located wholly below the said tubes and communicating with the outlet only through the restricted spaces.

4. In combination the casing, the grate extending acrossthe same, the tubes above the grate having small spaces between them, the walls extending from the edge of the grate to the edge of the tubes, said grate, tubes and walls inclosing the combustion-chamber Wholly therein, and an outlet leading from the casing, said combustion-chamber communieating with the said outlet only through the small spaces between the tubes.

, In witness whereof I have hereunto set my hand in presence of two witnesses. y

CHARLES ERNEST DAWSON. Witnesses:

ALBERT E. PARKER, FRANCIS J. BIGNELL. 

